The teenage girl craved French fries. So, standing at her kitchen range, she poured oil into a pan, turned up the heat, and then dashed upstairs -- for just a second, of course -- while it warmed up.

Distracted, she forgot about the pan.

Within minutes, the bubbling oil reached a flashpoint and set fire to the range. But fire did not race through the Olney house on July 26. Instead, it was quickly extinguished by a single fire sprinkler in the kitchen, ending the teenager's misadventure on a soggy note, but also preventing major property damage, or worse.

Visualizing what might have been, Chief Mike Love, fire marshal of Montgomery County Fire and Rescue Service, said, "The kids were upstairs. They could have been trapped up there. It would have taken some extraordinary measures on the fire department's part to get them out the windows."

Love's message: Residential fires move fast, can strike without warning, and kill -- claiming almost 3,400 Americans in 2002. Experts have long advocated a two-tiered defense of smoke detectors and automatic fire sprinklers. Studies cited by the National Fire Protection Association of Quincy, Mass., suggest that such a system reduces the risk of death in a home fire by more than 80 percent. Most houses, however, don't have sprinklers, leaving small, preventable fires free to cause wide damage.

In an age of health- and safety-conscious consumers, how can this technology gap exist? And what are the issues when retrofitting sprinklers into older homes?

An Image Issue

Few lifesaving technologies have suffered the negative image and consumer resistance inspired by sprinklers. According to Peg Paul, communications manager for the Quincy, Mass.-based Home Fire Sprinkler Coalition, sprinklers gone wild are a recurrent plot device in movies. Just when reformers gain traction on the consumer education front, Hollywood breathes new life into an old image.

In 2002, Ben Affleck made the impossible happen when he triggered every sprinkler in an office building in "Changing Lanes." Ditto Keanu Reeves in "The Matrix" in 1999 and gun-toting Bruce Willis in the 1988 blockbuster "Die Hard." Add to that list a Doritos commercial broadcast during the 1999 Super Bowl, which showed an impossibly hot, bikini-clad Ali Landry -- Miss USA 1996 -- setting off a row of sprinklers.

The message: Sprinklers are an iffy technology; don't trust them.

But experts say sprinkler technology is mature and safe -- and accidental activation uncommon. "A sprinkler system is more reliable than the plumbing system in a home," Paul said. "The likelihood of discharge because of manufacturing defect is extremely rare."

Chauncey Bowers, captain of the Prince George's County Fire/EMS Department, said his county bucked convention in 1989 when it required sprinklers in new single-family home construction. Montgomery County caught up at the start of 2004. No Virginia jurisdiction requires sprinklers in single-family residences, nor does the District of Columbia.

In Maryland, in addition to Montgomery and Prince George's counties, the city of Mount Airy in Carroll County mandates sprinklers in new single-family homes. "There are numerous other municipalities considering some form of residential fire sprinkler ordinances," said W. Faron Taylor, deputy state fire marshal.

According to Glenn Benarick, Fairfax County chief of fire prevention, sprinklers are optional in new single-family houses in Fairfax County. "Virginia state law prohibits any county or municipality from amending statewide building codes," he said. New multifamily homes and apartments are required to have sprinklers, however.

Bowers said, "Where residential sprinkler systems have been functional, [Prince George's County has] not had a single fire fatality since 1989." Notably, three Fairfax County residents who died in a mid-July condominium blaze perished in unsprinklered units. Sprinklers, fire experts said, would likely have bought them needed escape time.

What baffles the firefighters, said Pete Piringer, spokesman for the Montgomery County Fire Rescue Service, are homeowners who splurge on granite kitchen counters, wide-screen televisions or designer decks, yet skimp on technology that might save their lives -- and their expensive possessions. "A sprinkler system is like having a firefighter on duty 24/7," he said. "We think it's the single most important thing a family can do to protect themselves against fire. We know that the homes that are being built today in Montgomery County are going to be the historic homes of tomorrow, because they're not going to burn down."

Smoke detectors may warn, but they do not contain or extinguish fires. National pioneer Scottsdale, Ariz., required sprinklers in new single-family dwellings nearly 20 years ago. Today, more than 46,000 of the city's 83,000 single-family homes have sprinklers.

According to Jim Ford, assistant chief of the Scottsdale Rural Fire Department, smoke detectors simply are not enough. "If you're one of the high-risk groups -- elderly, impaired or disabled, or a child -- then a smoke alarm isn't really going to do anything for you," he said.

Montgomery County's Love noted that children often don't hear smoke detectors and some people forget to change detector batteries. Notably, most people who die in residential fires succumb to smoke inhalation.

A fire doubles in size each minute, so the first two or three minutes are critical. "If you have sprinklers in place, they will catch a fire in a small stage," Piringer said. "If it doesn't extinguish the fire, it will hold it in check until we get to it."

High-Tech Improvements

Dave Stroup, fire protection engineer for the National Institute of Standards and Technology, said sprinkler technology is faster and more effective than in the past. These heat-activated units are designed so that, at about 130 degrees, a cosmetic plate falls off the sprinkler head. Activation occurs a few seconds later, at about 155 to 165 degrees, when either a fusible metal link or liquid-filled capsule breaks and releases pressurized water.

Acknowledging consumer concern about water damage, Piringer shared his standard "better a mop than a body bag" message. "I'd rather have a sprinkler or two that discharge at 10 to 15 gallons of water a minute that can control a small fire," he said, "than have five or six 250-pound firefighters kicking my door down and pulling a hose that discharges 125 to 150 gallons a minute through my living room."

Sprinklers work on a zone defense, meaning that each head acts independently from the team to cover its own territory. Should a fire break out in a large living room, only the head nearest the fire will activate. Studies show that one or two sprinklers handle the vast majority of fires and that one head can typically cover a large living room.

Michael Peters, president of Advanced Fire Protection Systems in Glen Burnie, Md., said manufacturers today focus on both cosmetics and performance. "You don't even know they are there," he said. "There are many kinds of sprinkler heads: semi-recessed, concealed, even different colors."

He pointed to another way sprinklers help. "Smoke does more damage than the average fire," he said. "Water damage is far, far less than smoke damage."

Illustrating this point, the Home Fire Sprinkler Coalition makes available on its Web site a video sequence depicting the losses suffered by two households in fires. While the unsprinklered home incurs $125,000 in damage, the protected homeowners face a $3,000 mop-up.

Wade Tharrington, project manager for Fairfax-based American Automatic Sprinkler, said the cost for retrofitting a home depends on the size and complexity of the project. "We're basically looking at $2 to $2.50 a square foot," he said. "For a 4,000-square-foot house, figure about $8,000."

Homes not connected to a municipal water line can typically use well-based systems, he said, "as long as you get the required pressure."

Describing the installation of sprinklers in her two-story Colonial, the Home Fire Sprinkler Coalition's Paul said, "Because it was a retrofit job, it was easier for the installers to put the sprinklers in the walls than in the ceiling." Installations that route water pipes through attics require thick insulation to protect them from freezing temperatures.

Woody Stratton, fire programs manager for the U.S. Fire Administration, a branch of the Department of Homeland Security, discourages do-it-yourselfers. "We're too early in the game to make it a Home Depot- or Lowe's-type installation," he said.

Ford of the Scottsdale fire department said such installations are also typically illegal.

Underscoring the effectiveness of sprinklers, Ford noted a case in that city in which a man dumped a gallon of gasoline on his sleeping roommate, set the man ablaze and ran away. "The sprinkler put the fire out," Ford said. "[The victim] wasn't even admitted to the hospital."

The difference in fire damage without sprinklers, above, and with them, below, is dramatic. In a Home Fire Sprinkler Coalition example, an unsprinklered home faces $125,000 in repairs; the protected home has $3,000 in water damage.